U.S. patent application number 16/088416 was filed with the patent office on 2019-09-05 for gun microphone wind shield.
The applicant listed for this patent is TOMOEGAWA CO., LTD.. Invention is credited to Fukushi KAWAKAMI, Takayuki SANO.
Application Number | 20190273986 16/088416 |
Document ID | / |
Family ID | 59963916 |
Filed Date | 2019-09-05 |
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United States Patent
Application |
20190273986 |
Kind Code |
A1 |
KAWAKAMI; Fukushi ; et
al. |
September 5, 2019 |
GUN MICROPHONE WIND SHIELD
Abstract
There is provided a gun microphone that can shut off properly
wind noise such as whistling sounds while a gun microphone is used.
The gun microphone wind shield includes a second covering body that
defines a first space between the second covering body and a first
covering body and a third covering body that defines a second space
between the third covering body and the second covering body, and
forms a second longitudinal flow path that moves the air having
flowed into the second space along the longitudinal direction of
the second covering body and a first longitudinal flow path that
moves the air having flowed into the first space along the
longitudinal direction of the first covering body.
Inventors: |
KAWAKAMI; Fukushi;
(Hamamatsu-shi, Shizuoka, JP) ; SANO; Takayuki;
(Shizuoka-shi, Shizuoka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOMOEGAWA CO., LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
59963916 |
Appl. No.: |
16/088416 |
Filed: |
February 14, 2017 |
PCT Filed: |
February 14, 2017 |
PCT NO: |
PCT/JP2017/005381 |
371 Date: |
September 25, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04R 1/086 20130101;
H04R 1/326 20130101; H04R 1/08 20130101 |
International
Class: |
H04R 1/32 20060101
H04R001/32; H04R 1/08 20060101 H04R001/08 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2016 |
JP |
2016-065176 |
Claims
1. A gun microphone wind shield comprising: a first covering body
that covers a gun microphone, has an elongated shape, and contains
an acoustic transmissive material; a second covering body that
covers the first covering body, is arranged in a position separated
from the first covering body, has an elongated shape, contains an
acoustic transmissive material, and defines a first space between
the second covering body and the first covering body; and a third
covering body that covers the second covering body, is arranged in
a position separated from the second covering body, has an
elongated shape, contains an acoustic transmissive material, and
defines a second space between the third covering body and the
second covering body, wherein the acoustic transmissive material
contains a fiber material obtained by interlacing a raw material
containing fibers, blocks part of air in contact, and transmits the
remainder of the air, the second space has a second longitudinal
flow path in which air having flowed into the second space moves
along a longitudinal direction of the second covering body, and the
first space has a first longitudinal flow path in which air having
flowed into the first space moves along a longitudinal direction of
the first covering body.
2. The gun microphone wind shield according to claim 1, wherein an
elastic foaming body with open cells is provided in at least part
of the first space or the second space.
3. The gun microphone wind shield according to claim 1, wherein the
second space has a second circular flow path in which the air
having passed through the third covering body and flowed into the
second space moves along at least part of the circumference of the
second covering body.
4. The gun microphone wind shield according to claim 1, wherein the
first space has a first circular flow path in which the air having
passed through the second covering body and flowed into the first
space moves along at least part of the circumference of the first
covering body.
5. The gun microphone wind shield according to claim 1, wherein
longitudinal lengths of the first covering body and the second
covering body are larger than the distance of the first space or
the distance of the second space.
Description
TECHNICAL FIELD
[0001] The present invention relates to a wind shield used for a
gun microphone with directivity.
BACKGROUND ART
[0002] Gun microphones (shot-gun microphones) are used in many
cases to pick up sounds at a long distance. The gun microphone has
high directivity and can pick up sounds ahead of the gun microphone
while canceling out surrounding sounds.
[0003] In general, the gun microphone has a narrow and elongated
columnar interference tube. The gun microphone can pick up mainly
sounds ahead of the gun microphone by interfering with sounds
emitted from a sound source positioned on the lateral sides of the
gun microphone to cancel out the sounds in the interference
tube.
[0004] As described above, the gun microphone has an elongated
interference tube. Accordingly, when wind noise such as whistling
sounds is picked up by the gun microphone, the entire gun
microphone including the interference tube needs to be covered with
a wind shield.
[0005] As one of conventional wind shields, there is a wind shield
in which an almost cylindrical sponge has fibers implanted in the
internal diameter side. This wind shield is designed to be hard to
come off an elongated microphone due to the implanted fibers (for
example, refer to Patent Literature 1).
[0006] There is also a wind shield with a cage-shaped frame. The
cage-shaped frame forms a space from an elongated microphone and
supports the wind shield (for example, refer to Patent Literature
2).
[0007] Further, there is a wind shield that is made from an elastic
body with open cells and has a slide guide member on the inner
peripheral surface of the elastic body. The provision of the slide
guide member is intended to enhance the ease of attachment to and
detachment from an elongated microphone (for example, refer to
Patent Literature 3).
CITATION LIST
Patent Literatures
Patent Literature 1: JP 2006-60479 A
Patent Literature 2: JP 2012-175379 A
Patent Literature 3: JP 2008-187312 A
SUMMARY OF INVENTION
Technical Problem
[0008] As described above, various wind shields have been devised.
However, a wind shield made from an elastic body with open cells
such as sponge can initially decrease wind noise but suffers from
gradual aged deterioration due to moisture from rain or the like.
As the results, the wind shield is difficult to maintain its
characteristics.
[0009] The present invention is devised in light of the foregoing
problem. An object of the present invention is to provide a gun
microphone wind shield that is attachable to an elongated gun
microphone and can properly shut off wind noise such as whistling
sounds when being attached to a gun microphone.
Solution to Problem
[0010] An aspect of a gun microphone wind shield according to the
present invention includes: a first covering body that covers a gun
microphone, has an elongated shape, and contains an acoustic
transmissive material; a second covering body that covers the first
covering body, is arranged in a position separated from the first
covering body, has an elongated shape, contains an acoustic
transmissive material, and defines a first space between the second
covering body and the first covering body; a third covering body
that covers the second covering body, is arranged in a position
separated from the second covering body, has an elongated shape,
contains an acoustic transmissive material, and defines a second
space between the third covering body and the second covering body,
wherein the acoustic transmissive material contains a fiber
material obtained by interlacing a raw material containing fibers,
blocks part of air in contact, and transmits the remainder of the
air, wherein the second space has a second longitudinal flow path
in which air having flowed into the second space moves along a
longitudinal direction of the second covering body, and the first
space has a first longitudinal flow path in which air having flowed
into the first space moves along a longitudinal direction of the
first covering body.
[0011] The acoustic transmissive material contains a fiber material
obtained by interlacing a raw material containing fibers, which
prevents or reduces aged deterioration over a long period of
time.
[0012] The second space has the second longitudinal flow path in
which the air having flowed into the second space moves along the
longitudinal direction of the second covering body. Accordingly,
the air having flowed into the second space moves in the
longitudinal direction, which makes the air less likely to leak
from the second space to the first space.
[0013] The first space has the first longitudinal flow path in
which the air having flowed into the first space moves along the
longitudinal direction of the first covering body. Accordingly, the
air having flowed into the first space moves in the longitudinal
direction, which makes the air less likely to leak from the first
space to the gun microphone and shut off properly whistling
sounds.
Advantageous Effects of Invention
[0014] The gun microphone wind shield according to the present
invention can shut off properly whistling sounds even when being
used for a long period of time.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a diagram schematically illustrating a gun
microphone wind shield 100 according to an embodiment. FIG. 1A is a
cross-sectional view of the gun microphone wind shield 100, FIG. 1B
is a cross-sectional view of flows of air moving along a
longitudinal direction of the gun microphone wind shield 100, and
FIG. 1C is a cross-sectional view of flows of air moving along a
circumferential direction of the gun microphone wind shield
100.
[0016] FIG. 2 is a perspective view of the entire gun microphone
wind shield 100.
[0017] FIG. 3 is a perspective view of a first acoustic
transmissive body 110, a second acoustic transmissive body 120, a
third acoustic transmissive body 130, an elastic foaming body 140,
a basket 150, and a gun microphone 300 stored in the gun microphone
wind shield 100.
[0018] FIG. 4 is a cross-sectional view of a configuration of the
gun microphone wind shield 100 taken along the circumferential
direction.
[0019] FIG. 5 is a cross-sectional view of the gun microphone wind
shield 100 taken along the longitudinal direction.
[0020] FIG. 6 is a cross-sectional view (FIG. 6A) of longitudinal
flows of air and is a cross-sectional view (FIG. 6B) of
circumferential flows of air in a first space SP10 and a second
space SP20.
[0021] FIG. 7 is a perspective view of a first acoustic
transmissive body 110, a second acoustic transmissive body 120, a
third acoustic transmissive body 130, a basket 150, and a gun
microphone 300 stored in a gun microphone wind shield 200.
[0022] FIG. 8 is a cross-sectional view of the gun microphone wind
shield 200 taken along the circumferential direction.
[0023] FIG. 9 is a cross-sectional view of the gun microphone wind
shield 200 taken along the longitudinal direction.
[0024] FIG. 10 is a diagram schematically illustrating a component
LP10 moving along the longitudinal direction and a component AP10
moving along the circumferential direction in the first acoustic
transmissive body 110 and a component LP20 moving along the
longitudinal direction and a component AP20 moving along the
circumferential direction in the second acoustic transmissive body
120.
[0025] FIG. 11 is a side view of the basket 150 and a grip
vibration-proof structure 400.
[0026] FIG. 12 is a perspective view of the basket 150 and the grip
vibration-proof structure 400.
[0027] FIG. 13 is an enlarged side view of a structure of a grip
portion 410.
[0028] FIG. 14 is a perspective view of the entire grip
vibration-proof structure 400.
[0029] FIG. 15 is a front view of a state in which the first
acoustic transmissive body 110 and the second acoustic transmissive
body 120 are attached to an elastic hold body 434.
[0030] FIG. 16 is a perspective view of a state in which the first
acoustic transmissive body 110 is attached to the elastic hold body
434.
[0031] FIG. 17 is a perspective view of an end of the basket
150.
DESCRIPTION OF EMBODIMENTS
[0032] Embodiments will be described below with reference to the
drawings. FIG. 1 is a diagram schematically illustrating a first
aspect of the present invention. FIG. 1A is a cross-sectional view
of the gun microphone wind shield 100, FIG. 1B is a cross-sectional
view of flows of air moving along a longitudinal direction of the
gun microphone wind shield 100, and FIG. 1C is a cross-sectional
view of flows of air moving along a circumferential direction of
the gun microphone wind shield 100.
First Aspect
[0033] According to a first aspect of the present invention, as
illustrated in FIGS. 1A, 1B, and 1C, there is provided a gun
microphone wind shield 10 including: a first covering body 11 (for
example, a first acoustic transmissive body 110 described later or
the like) that covers a gun microphone 30 (for example, a gun
microphone 300 as described later or the like), has an elongated
shape, and contains an acoustic transmissive material; a second
covering body 12 (for example, a second acoustic transmissive body
120 described later or the like) that covers the first covering
body 11, is arranged in a position separated from the first
covering body 11, has an elongated shape, contains an acoustic
transmissive material, and defines a first space SP1 (for example,
a first space SP10 described later or the like) between the second
covering body 12 and the first covering body 11; a third covering
body 13 (for example, a third acoustic transmissive body 130
described later or the like) that covers the second covering body
12, is arranged in a position separated from the second covering
body 12, has an elongated shape, contains an acoustic transmissive
material, and defines a second space SP2 (for example, a second
space SP20 described later or the like) between the third covering
body 13 and the second covering body 12, wherein the acoustic
transmissive material contains a fiber material obtained by
interlacing a raw material containing fibers, blocks part of air in
contact, and transmits the remainder of the air, wherein the second
space SP2 has a second longitudinal flow path LP2 (for example, a
component LP20 moving along the longitudinal direction described
later or the like) in which air having flowed into the second space
SP2 moves along a longitudinal direction of the second covering
body 12, and the first space SP1 has a first longitudinal flow path
LP1 (for example, a component LP10 moving along the longitudinal
direction described later or the like) in which air having flowed
into the first space SP1 moves along a longitudinal direction of
the first covering body 11.
Gun Microphone Wind Shield 10 and Gun Microphone 30
[0034] The gun microphone wind shield 10 is a wind shield for
covering the gun microphone 30. The gun microphone 30 is a
microphone with directivity for picking up sounds emitted from a
desired sound source. The gun microphone 30 has an interference
tube or the like and is generally elongated in shape. The gun
microphone wind shield 10 includes a first covering body 11, a
second covering body 12, and a third covering body 13.
Acoustic Transmissive Material
[0035] Each of the first covering body 11, the second covering body
12, and the third covering body 13 contains an acoustic
transmissive material. The acoustic transmissive material includes
a fiber material. The fiber material is obtained by interlacing a
raw material containing fibers. The acoustic transmissive material
blocks part of contacting air and transmits the remainder of the
air.
[0036] The materials for the first covering body 11, the second
covering body 12, and the third covering body 13 may be the same or
different to one other. In addition, the same materials may be
different in properties such as density and interlacing mode. The
ingredients and substances of the acoustic transmissive material
can be decided in such a manner as to shut off whistling sounds
appropriately and pick up sounds emitted from a desired sound
source.
[0037] Using the acoustic transmissive materials for the first
covering body 11, the second covering body 12, and the third
covering body 13 makes it possible to prevent or reduce aged
deterioration over a long period of time.
Outer Shapes of the First Covering Body 11, the Second Covering
Body 12, and the Third Covering Body 13
[0038] The first covering body 11, the second covering body 12, and
the third covering body 13 are elongated in shape. The shapes of
the first covering body 11, the second covering body 12, and the
third covering body 13 can be decided according to the elongated
shape of the gun microphone 30.
[0039] The first covering body 11, the second covering body 12, and
the third covering body 13 are desirably almost circular
cylindrical in shape. Further, the first covering body 11, the
second covering body 12, and the third covering body 13 are not
limited to an almost circular cylindrical shape but may have any of
various cylindrical shapes such as a square cylinder or an elliptic
cylinder.
[0040] The longitudinal lengths of the first covering body 11, the
second covering body 12, and the third covering body 13 are
preferably the same. In this case, the longitudinal length of the
first space SP1 and the longitudinal length of the second space SP2
described later become the same. This makes it possible to separate
flows of air in the first space SP1 from flows of air in the second
space SP2 to control individually the separate flows of air.
[0041] The longitudinal lengths of the first covering body 11, the
second covering body 12, and the third covering body 13 may be
different to one other. For example, when the longitudinal length
of the second covering body 12 is shorter than the longitudinal
lengths of the first covering body 11 and the third covering body
13, the boundary between the first space SP1 and the second space
SP2 is absent in a region near the ends of the first covering body
11 and the third covering body 13, and a space without the second
covering body 12 is formed between the first covering body 11 and
the third covering body 13. In this case, the air in the first
space SP1 and the second space SP2 can move directly via the space
without the second covering body 12. In this way, when the
longitudinal lengths of the first covering body 11, the second
covering body 12, and the third covering body 13 are different, it
is easy to move the air.
First Covering Body 11
[0042] The first covering body 11 covers the gun microphone 30. The
gun microphone 30 is generally elongated in shape and has an
interferential opening along a longitudinal direction. The first
covering body 11 needs to cover the gun microphone 30 in such a
manner as to overlap at least part of the interferential opening.
The first covering body 11 preferably covers the gun microphone 30
so as to overlap the entire interferential opening.
[0043] The longitudinal length of the first covering body 11 is
preferably larger than the longitudinal length of the gun
microphone 30. The first covering body 11 preferably covers the gun
microphone 30 in such a manner as to store the entire gun
microphone 30 except for a cable and the like connected to the gun
microphone 30. Further, the first covering body 11 is desirably
positioned to be concentric (coaxial) to the gun microphone 30 to
cover the entire gun microphone 30.
Second Covering Body 12
[0044] The second covering body 12 covers the first covering body
11. The second covering body 12 preferably stores the entire first
covering body 11 and covers the first covering body 11. The second
covering body 12 may be configured to cover part of the first
covering body 11 as far as it can shut off whistling sounds.
[0045] The longitudinal length of the second covering body 12 is
more preferably the same as the longitudinal length of the first
covering body 11. The second covering body 12 is desirably
positioned to be concentric (coaxial) to the first covering body 11
along the longitudinal direction of the first covering body 11 to
store and cover the entire first covering body 11.
[0046] The second covering body 12 is arranged in a position
separated from the first covering body 11. The first space SP1 is
formed by the gap between the first covering body 11 and the second
covering body 12. A distance DT1 between the first covering body 11
and the second covering body 12 may not be constant. The first
space SP1 is formed between the first covering body 11 and the
second covering body 12 to make the air less likely to leak to the
inside of the first covering body 11, thereby shutting off
whistling sounds. Arranging the second covering body 12 to be
concentric (coaxial) to the first covering body 11 makes the
distance DT1 constant. Making the distance DT1 constant between the
first covering body 11 and the second covering body 12 allows the
air having entered the first space SP1 to be dispersed evenly.
Third Covering Body 13
[0047] The third covering body 13 covers the second covering body
12. The third covering body 13 preferably stores the entire second
covering body 12 and covers the second covering body 12. The third
covering body 13 may be configured to cover part of the second
covering body 12 as far as it can shut off whistling sounds.
[0048] The longitudinal length of the third covering body 13 is
more preferably the same as the longitudinal length of the second
covering body 12. The third covering body 13 is desirably
positioned to be concentric (coaxial) to the second covering body
12 along the longitudinal direction of the second covering body 12
to store and cover the entire second covering body 12.
[0049] The third covering body 13 is arranged in a position
separated from the second covering body 12. The second space SP2 is
formed by the gap between the second covering body 12 and the third
covering body 13. A distance DT2 between the second covering body
12 and the third covering body 13 may not be constant. The second
space SP2 is formed between the second covering body 12 and the
third covering body 13 to make the air less likely to leak to the
inside of the second covering body 12, thereby shutting off
whistling sounds. Arranging the third covering body 13 to be
concentric (coaxial) to the second covering body 12 makes the
distance DT2 constant. Making the distance DT2 constant between the
second covering body 12 and the third covering body 13 allows the
air having entered the second space SP2 to be dispersed evenly.
Second Longitudinal Flow Path LP2
[0050] As illustrated in FIG. 1B, a second longitudinal flow path
LP2 is formed in the second space SP2. The second longitudinal flow
path LP2 is a path in which the air having flowed into the second
space SP2 moves along the longitudinal direction of the second
covering body 12.
[0051] The second space SP2 is a space formed between the second
covering body 12 and the third covering body 13. The second
covering body 12 and the third covering body 13 have an elongated
shape, and the second space SP2 also has an elongated shape. The
second space SP2 acts as a region for facilitating the movement of
the air in the longitudinal direction of the second space SP2. The
air having flowed into the second space SP2 is guided by contact
with the second covering body 12 and the third covering body 13 to
move in the second space SP2 along the longitudinal direction. The
path of the movement of the air constitutes the second longitudinal
flow path LP2.
[0052] The second longitudinal flow path LP2 does not always need
to extend along the longitudinal direction of the second space SP2
but includes at least a portion along the longitudinal direction.
For example, the second longitudinal flow path LP2 may include a
path toward to the second covering body 12, a path toward to the
third covering body 13 or a path meandering through the second
space SP2 as far as it includes a portion along the longitudinal
direction.
[0053] The second longitudinal flow path LP2 may be short. The
second longitudinal flow path LP2 does not need to reach the end of
the second space SP2. The second longitudinal flow path LP2
includes at least a portion along the longitudinal direction of the
second space SP2.
First Longitudinal Flow Path LP1
[0054] As illustrated in FIG. 1B, a first longitudinal flow path
LP1 is formed in the first space SP1. The first longitudinal flow
path LP1 is a path in which the air having flowed into the first
space SP1 moves along the longitudinal direction of the first
covering body 11.
[0055] The first space SP1 is a space formed between the first
covering body 11 and the second covering body 12. The first
covering body 11 and the second covering body 12 have an elongated
shape, and the first space SP1 also has an elongated shape. The
first space SP1 acts as a region for facilitating the movement of
the air in the longitudinal direction of the first space SP1. The
air having flowed into the first space SP1 is guided by contact
with the first covering body 11 and the second covering body 12 to
move in the first space SP1 along the longitudinal direction. The
path of the movement of the air constitutes the first longitudinal
flow path LP1.
[0056] The first longitudinal flow path LP1 does not always need to
extend along the longitudinal direction of the first space SP1 but
includes at least a portion along the longitudinal direction. For
example, the first longitudinal flow path LP1 may include a path
toward to the first covering body 11, a path toward to the second
covering body 12 or a path meandering through the first space SP1
as far as it includes a portion along the longitudinal
direction.
[0057] The first longitudinal flow path LP1 may be short. The first
longitudinal flow path LP1 does not need to reach the end of the
first space SP1. The first longitudinal flow path LP1 includes at
least a portion along the longitudinal direction of the first space
SP1.
Flows of Air
[0058] When the gun microphone wind shield 100 is used outdoors, a
flow of air due to wind or the like contacts the gun microphone
wind shield 100. Specifically, the air contacts the third covering
body 13. The third covering body 13 contains the acoustic
transmissive material that blocks part of the air in contact and
transmits the remainder of the air. The air having passed through
the third covering body 13 enters the second space SP2. The air
having entered the second space SP2 is guided by contact with the
second covering body 12 and the third covering body 13 and moves in
the second space SP2 along the longitudinal direction. The movement
of the air forms the second longitudinal flow path LP2.
[0059] In this way, part of the air in contact with the third
covering body 13 is blocked and the remainder passes through the
third covering body 13. Since only part of the air in contact with
the third covering body 13 passes through the third covering body
13, the third covering body 13 can reduce the amount of the air
entering the second space SP2 and suppress the momentum of the air.
Further, the air having entered the second space SP2 gradually
slows down by contact with the second covering body 12 and the
third covering body 13. Accordingly, the momentum of the air can be
suppressed.
[0060] The second covering body 12 contains the acoustic
transmissive material that blocks part of the air in contact and
transmits the remainder of the air. Some of the air having entered
the second space SP2 may pass through the second covering body 12
depending on its amount and momentum.
[0061] The air having passed through the second covering body 12
enters the first space SP1. The air having entered the first space
SP1 is guided by contact with the first covering body 11 and the
second covering body 12 and moves in the first space SP1 along the
longitudinal direction. The movement of the air forms the first
longitudinal flow path LP1.
[0062] In this way, part of the air in contact with the second
covering body 12 is blocked and the remainder passes through the
second covering body 12. Since only part of the air in contact with
the second covering body 12 passes through the second covering body
12, the second covering body 12 can reduce the amount of the air
entering the first space SP1 and suppress the momentum of the air.
Further, the air having entered the first space SP1 gradually slows
down by contact with the first covering body 11 and the second
covering body 12. Accordingly, the momentum of the air can be
suppressed.
[0063] The gun microphone 30 is covered with the first covering
body 11. Accordingly, even when the air enters the first space SP1,
the first covering body 11 blocks the passage of the air to shut
off whistling sounds properly.
[0064] Even when the gun microphone wind shield 100 is used
outdoors, the second space SP2 and the first space SP1 can
gradually reduce the amount of air and suppress the momentum of the
air to block the passage of the air to the gun microphone 30 and
shut off whistling sounds properly.
Second Aspect
Elastic Foaming Body
[0065] According to a second aspect of the present invention in the
first aspect of the present invention, an elastic foaming body with
open cells (for example, an elastic foaming body 140 described
later or the like) is provided in at least part of the first space
SP1 or the second space SP2.
[0066] The elastic foaming body is preferably provided in at least
one of the first space SP1 and the second space SP2. The elastic
foaming body has open cells. The elastic foaming body can control
the direction of a flow of air with the open cells, or block and
slow down a flow of air gradually due to collision with the open
cells. In this way, the elastic foaming body can change the
direction of the air and/or suppress the velocity of the air.
[0067] Accordingly, the elastic foaming body can further change the
direction and velocity of the air having entered the first space
SP1 or the second space SP2.
Third Aspect
Second Circular Flow Path AP2
[0068] As illustrated in FIGS. 1A, 1B, and 1C, according to a third
aspect of the present invention in the first aspect of the present
invention, the second space SP2 has a second circular flow path AP2
(for example, a component AP20 moving along the circumferential
direction described later or the like) in which the air having
flowed into the second space SP2 through the third covering body
moves along at least part of the circumference of the second
covering body 12.
[0069] As illustrated in FIG. 1C, the second space SP2 has the
second circular flow path AP2. The second circular flow path AP2 is
a path in which the air having flowed into the second space SP2
moves along the direction that circles around the second covering
body 12.
[0070] The second space SP2 is a space formed between the second
covering body 12 and the third covering body 13. The third covering
body 13 is arranged in a position separated from the second
covering body 12, and the second space SP2 has a shape that circles
around the second covering body 12. The second space SP2 acts as a
region for facilitating the movement of the air in the direction
that circles around the second covering body 12. The air having
flowed into the second space SP2 is guided by contact with the
second covering body 12 and the third covering body 13 to move
along the direction that circles around the second covering body
12. The path of the movement of the air constitutes the second
circular flow path AP2.
[0071] The second circular flow path AP2 does not always need to
extend along the direction that circles around the second covering
body 12 but includes at least a portion along the circling
direction. For example, the second circular flow path AP2 may
include a path toward to the second covering body 12, a path toward
to the third covering body 13 or a path meandering through the
second space SP2 as far as it includes a portion along the circling
direction.
[0072] The second circular flow path AP2 may be short. The second
circular flow path AP2 does not need to circle around the entire
second covering body 12. The second circular flow path AP2 includes
at least a portion in which the air moves along the direction that
circles around the second covering body 12.
The Second Longitudinal Flow Path LP2 and the Second Circular Flow
Path AP2
[0073] As described above, the second space SP2 has the second
longitudinal flow path LP2 and the second circular flow path AP2.
The second longitudinal flow path LP2 and the second circular flow
path AP2 refer to components of the movement directions of the air
flowing in the second space SP2. The second longitudinal flow path
LP2 refers to the component of the air that flows and moves in the
second space SP2 along the longitudinal direction of the second
covering body 12. The second circular flow path AP2 refers to the
component of the air that flows and moves in the second space SP2
along the direction that circles around the second covering body
12. The air flowing in the second space SP2 has the component that
moves along the longitudinal direction of the second covering body
12 and the component that moves along the direction that circles
around the second covering body 12.
Fourth Aspect
First Circular Flow Path AP1
[0074] As illustrated in FIGS. 1A, 1B, and 1C, according to a
fourth aspect of the present invention in the first aspect of the
present invention, the first space SP1 has a first circular flow
path AP1 (for example, a component AP10 moving along the
circumferential direction described later or the like) in which the
air having flowed into the first space SP1 through the second
covering body 12 moves along at least part of the circumference of
the first covering body 11.
[0075] As illustrated in FIG. 1C, the first space SP1 has a first
circular flow path AP1. The first circular flow path AP1 is a path
in which the air having flowed into the first space SP1 moves along
the direction that circles around the first covering body 11.
[0076] The first space SP1 is a space formed between the first
covering body 11 and the second covering body 12. The second
covering body 12 is arranged in a position separated from the first
covering body 11, and the first space SP1 has a shape that circles
around the first covering body 11. The first space SP1 acts as a
region for facilitating the movement of the air in the direction
that circles around the first covering body 11. The air having
flowed into the first space SP1 is guided by contact with the first
covering body 11 and the second covering body 12 to move along the
direction that circles around the first covering body 11. The path
of the movement of the air constitutes the first circular flow path
AP1.
[0077] The first circular flow path AP1 does not always need to
extend along the direction that circles around the first covering
body 11 but includes at least a portion along the circling
direction. For example, the first circular flow path AP1 may
include a path toward to the first covering body 11, a path toward
to the second covering body 12 or a path meandering through the
first space SP1 as far as it includes a portion along the circling
direction.
[0078] The first circular flow path AP1 may be short. The first
circular flow path AP1 does not need to circle around the entire
first covering body 11. The first circular flow path AP1 includes
at least a portion in which the air moves along the direction that
circles around the first covering body 11.
The First Longitudinal Flow Path LP1 and the First Circular Flow
Path AP1
[0079] As described above, the first space SP1 has the first
longitudinal flow path LP1 and the first circular flow path AwP1.
The first longitudinal flow path LP1 and the first circular flow
path AP1 refer to components of the movement directions of the air
flowing in the first space SP1. The first longitudinal flow path
LP1 refers to the component of the air that flows and moves in the
first space SP1 along the longitudinal direction of the first
covering body 11. The first circular flow path AP1 refers to the
component of the air that flows and moves in the first space SP1
along the direction that circles around the first covering body 11.
The air flowing in the first space SP1 has the component that moves
along the longitudinal direction of the first covering body 11 and
the component that moves along the direction that circles around
the first covering body 11.
Fifth Aspect
The Longitudinal Length of the First Covering Body 11 and the
Longitudinal Length of the Second Covering Body 12
[0080] According to a fifth aspect of the present invention in the
first aspect of the present invention, the longitudinal lengths of
the first covering body 11 and the second covering body 12 are
designed to be larger than a distance of the first space SP1 or a
distance of the second space SP2.
[0081] The longitudinal lengths of the first covering body 11 and
the second covering body 12 are larger than the distance of the
first space SP1 or the distance of the second space SP2.
[0082] The distance of the first space SP1 constitutes the distance
DT1 between the first covering body 11 and the second covering body
12. When the first covering body 11 and the second covering body 12
are columnar in shape and are concentric (coaxial) to each other,
the distance of the first space SP1 is constant.
[0083] When the distance of the first space SP1 is not constant, a
characteristic distance may be used. For example, the first space
SP1 may have an average distance, a maximum distance, or a minimum
distance.
[0084] The distance of the second space SP2 constitutes the
distance DT2 between the second covering body 12 and the third
covering body 13. When the second covering body 12 and the third
covering body 13 are columnar in shape and are concentric (coaxial)
to each other, the distance of the second space SP2 is
constant.
[0085] When the distance of the second space SP2 is not constant, a
characteristic distance may be used. For example, the first space
SP1 may have an average distance, a maximum distance, or a minimum
distance.
[0086] The first covering body 11 and the second covering body 12
are elongated in shape. The length of the first covering body 11
may be sufficiently larger than the distance of the first space
SP1. Specifically, even the distance of the first space SP1 is made
short, the longitudinal length of the first space SP1 can be
ensured, which allows the first space SP1 to act as a region for
moving the incoming air in the longitudinal direction. The length
of the second covering body 12 may be sufficiently larger than the
distance of the second space SP2. Specifically, even the distance
of the second space SP2 is made short, the longitudinal length of
the second space SP2 can be ensured, which allows the second space
SP2 to act as a region for moving the incoming air in the
longitudinal direction.
[0087] The distance of the second space SP2 can be set so that the
air is less likely to flow into the first space SP1 according to
the longitudinal length of the second covering body 12, the
longitudinal length of the third covering body 13, and the presence
or absence of an elastic foaming body.
[0088] The distance of the first space SP1 can be set so that the
air is less likely to flow into the gun microphone 30 according to
the longitudinal length of the first covering body 11, the
longitudinal length of the second covering body 12, and the
presence or absence of an elastic foaming body.
Sixth Aspect
[0089] A sixth aspect of the present invention further includes a
fourth covering body (for example, a basket 150 described later or
the like) that has an elongated shape, covers and protects the
third covering body, and has a sound transmissive opening that
transmits sounds.
[0090] The fourth covering body has an elongated shape and covers
and protects the third covering body. The fourth covering body
preferably covers the entire third covering body. The fourth
covering body has the sound transmissive opening that transmits
sounds. The fourth covering body can protect the third covering
body from deformation and breakage. The fourth covering body has
the sound transmissive opening so that sounds emitted from a sound
source can reach the gun microphone 300 without being attenuated or
deteriorated.
Seventh Aspect
[0091] A seventh aspect of the present invention further includes
an elastic hold portion (for example, an elastic hold body 434
described later or the like) that holds elastically the first
covering body 11 and the second covering body 12.
[0092] The elastic hold portion holds elastically the first
covering body 11 and the second covering body 12. By elastically
holding the first covering body 11 and the second covering body 12,
the elastic hold portion can absorb external shock and prevent the
shock from being picked up as noise by the gun microphone 300 due
to the vibration of the first covering body 11 and the second
covering body 12. In the embodiment, the shock includes shock
resulting from a physical collision and sounds generated by wind
and propagated as vibration through a solid object (hereinafter,
called solid-borne sounds or solid-borne noise). The solid-borne
sounds are picked up as wind noise.
Eighth Aspect
[0093] An eighth aspect of the present invention further includes a
fixed-shape hold portion (for example, brackets 440 described later
or the like) that is provided in the elastic hold portion, retains
the first covering body 11 and the second covering body 12 to hold
the shapes of the first covering body 11 and the second covering
body 12, and keep a distance (for example, the first space SP1
described later or the like) between the first covering body 11 and
the second covering body 12
[0094] The fixed-shape hold portion is provided in the elastic hold
portion to retain the first covering body 11 and the second
covering body 12 and hold the shapes of the first covering body 11
and the second covering body 12. The fixed-shape hold portion keeps
the distance between the first covering body 11 and the second
covering body 12. For example, even when the first covering body 11
and the second covering body 12 are made from members likely to
deform, the first covering body 11 and the second covering body 12
can be kept in their fixed shapes so that the distance between them
is kept. Keeping the distance between the first covering body 11
and the second covering body 12 makes it possible to form the
longitudinal flow path and the circular flow path in which the
incoming air can move.
Ninth Aspect
[0095] The first covering body 11 may have a gun microphone hold
portion (for example, the inside of a first acoustic transmissive
body 110 described later or the like) that stores and holds the gun
microphone.
[0096] The first covering body 11 may have the gun microphone hold
portion. The gun microphone hold portion stores and holds the gun
microphone in the first covering body 11. This makes it possible to
store the gun microphone in the first covering body 11 without the
use of a separate member such as an adapter for attaching the gun
microphone to the first covering body 11, which allows the gun
microphone to be attached and detached in an easy and simple
manner.
Tenth Aspect
[0097] A tenth aspect of the present invention further includes a
grip portion (for example, a grip portion 410 described later or
the like) that can be supported by the user and is detachably
coupled to the elastic hold portion via the fourth covering
body.
[0098] The grip portion is a member that is supportable by the
user. For example, the grip portion can be handheld and supported
by the user. The grip portion is detachably coupled to the elastic
hold portion. The grip portion is coupled to the elastic hold
portion with the fourth covering body therebetween. In other words,
while the grip portion is coupled to the elastic hold portion, the
fourth covering body is sandwiched between the grip portion and the
elastic hold portion. The grip portion can be attached as necessary
to simplify the handling of the gun microphone wind shield during
transportation.
Eleventh Aspect
[0099] An eleventh aspect of the present invention further includes
a grip portion elastic hold body (for example, a vibration absorber
416 described later or the like) that is provided between the
fourth covering body and the grip portion to hold elastically the
fourth covering body.
[0100] The grip portion elastic hold body is an elastically
deformable member to hold elastically the fourth covering body. The
grip portion elastic hold body is provided between the fourth
covering body and the grip portion. Even when shock or solid-borne
sounds are applied to the grip portion, the grip portion elastic
hold body can absorb the solid-borne sounds and shock to prevent
the solid-borne sounds and shock from transferring to the fourth
covering body and being picked up as noise by the gun microphone
300.
First Embodiment
[0101] First, a gun microphone wind shield 100 according to a first
embodiment will be described. The gun microphone wind shield 100 is
different from a gun microphone wind shield 200 according to a
second embodiment described later in the presence or absence of an
elastic foaming body 140 in a second space SP20.
[0102] FIG. 2 is a perspective view of the entire gun microphone
wind shield 100. FIG. 3 is a perspective view of a first acoustic
transmissive body 110, a second acoustic transmissive body 120, a
third acoustic transmissive body 130, an elastic foaming body 140,
a basket 150, and a gun microphone 300 stored in the gun microphone
wind shield 100. FIG. 4 is a cross-sectional view of the gun
microphone wind shield 100 taken along a circumferential direction.
FIG. 5 is a cross-sectional view of the gun microphone wind shield
100 taken along a longitudinal direction. FIG. 6 is a cross-
sectional view (FIG. 6A) of longitudinal flows of air and is a
cross-sectional view (FIG. 6B) of circumferential flows of air in a
first space SP10 and a second space SP20.
Gun Microphone Wind Shield 100
[0103] The gun microphone wind shield 100 according to the first
embodiment is a wind shield for use in the gun microphone 300. The
gun microphone 300 has high directivity and can cancel out
surrounding noise and pick up sounds ahead of the gun microphone
300.
Gun Microphone (Shot-Gun Microphone) 300
[0104] As illustrated in FIG. 3, the gun microphone 300 has an
almost columnar and elongated outer shape. The gun microphone 300
mainly has a microphone body 310 and an interference tube 320.
[0105] The interference tube 320 has an elongated, almost
cylindrical shape. The interference tube 320 has a first end 330
and a second end 340 along the longitudinal direction. The first
end 330 has an opening 332. Directing the opening 332 to a sound
source as a sound-pickup target makes it possible to transfer
sounds emitted from the sound source to the inside of the
interference tube via the opening 332.
[0106] The interference tube 320 has the second end 340 connected
to the microphone body 310 having a diaphragm. The diaphragm
vibrates on receipt of the sounds propagated through the
interference tube 320. The microphone body 310 converts the
vibration of the diaphragm into an electric signal and outputs the
same as an audio signal.
[0107] Further, the side surface of the interference tube 320 has a
plurality of slits 350. The sounds emitted from a sound source
positioned on the lateral side of the gun microphone 300 (the
interference tube 320) pass through the plurality of slits 350 and
enter the inside of the interference tube 320. The sounds having
passed through the plurality of slits 350 interfere with and cancel
out each other in the interference tube. The sounds emitted from a
sound source on the lateral side of the gun microphone 300 are not
sound-pickup targets. Causing the sounds having passed through the
plurality of slits 350 to cancel out each other prevents the sounds
from reaching the microphone body 310. In this way, the gun
microphone 300 includes the interference tube 320 to pick up sounds
with enhanced directivity.
[0108] When the gun microphone is used outdoors, a flow of air such
as wind is likely to contact not only the opening 332 but also the
interference tube 320 in the gun microphone 300. As described
above, the interference tube 320 has the plurality of slits 350 in
the side surface, and thus a flow of air such as wind is likely to
enter the interference tube 320 via the plurality of slits 350.
When the air flows into the interference tube 320, the diaphragm of
the microphone body 310 is likely to vibrate and cause wind noise
due to the flow of the air. Accordingly, the gun microphone wind
shield 100 needs to cover the entire gun microphone 300 including
the interference tube 320.
Main Components of the Gun Microphone Wind Shield 100
[0109] As illustrated in FIG. 3, the gun microphone wind shield 100
mainly has the first acoustic transmissive body 110, the second
acoustic transmissive body 120, the third acoustic transmissive
body 130, the elastic foaming body 140, and the basket 150. As
described later, the first acoustic transmissive body 110, the
second acoustic transmissive body 120, the third acoustic
transmissive body 130, the elastic foaming body 140, and the basket
150 are all elongated in shape and are almost concentric (almost
coaxial) to one another.
The First Acoustic Transmissive Body 110, the Second Acoustic
Transmissive Body 120, and the Third Acoustic Transmissive Body
130
[0110] The first acoustic transmissive body 110, the second
acoustic transmissive body 120, and the third acoustic transmissive
body 130 are all formed by curving an almost thin sheet-like
acoustic transmissive member into a cylindrical shape. The acoustic
transmissive member blocks the passage of part of contacting air.
The remaining unblocked air passes through the acoustic
transmissive member. The acoustic transmissive member will be
described later in detail.
Shape and Size
[0111] As illustrated in FIGS. 3, 4, and 5, the first acoustic
transmissive body 110, the second acoustic transmissive body 120,
and the third acoustic transmissive body 130 have an elongated and
almost cylindrical shape. The first acoustic transmissive body 110,
the second acoustic transmissive body 120, and the third acoustic
transmissive body 130 are different in thickness. The first
acoustic transmissive body 110 is the thinnest, the second acoustic
transmissive body 120 is thicker, and the third acoustic
transmissive body 130 is the thickest.
[0112] In other words, the first acoustic transmissive body 110,
the second acoustic transmissive body 120, and the third acoustic
transmissive body 130 are different in radius (diameter). The
radius (diameter) of the first acoustic transmissive body 110 is
the smallest, the radius (diameter) of the third acoustic
transmissive body 130 is the largest, and the radius (diameter) of
the second acoustic transmissive body 120 is larger than the radius
(diameter) of the first acoustic transmissive body 110 and smaller
than the radius (diameter) of the third acoustic transmissive body
130.
[0113] In addition, the first acoustic transmissive body 110, the
second acoustic transmissive body 120, and the third acoustic
transmissive body 130 are almost identical in longitudinal length
(the height of the cylinder). The longitudinal ends of the first
acoustic transmissive body 110, the second acoustic transmissive
body 120, and the third acoustic transmissive body 130 can be
aligned with one another.
[0114] A sound source-side end 112 of the first acoustic
transmissive body 110, a sound source-side end 122 of the second
acoustic transmissive body 120, and a sound source-side end 132 of
the third acoustic transmissive body 130 are all blocked with the
acoustic transmissive member. This makes the incoming air via a
leading end portion 152 of the basket 150 less likely to enter the
first acoustic transmissive body 110, the second acoustic
transmissive body 120, and the third acoustic transmissive body
130.
[0115] An end 114 of the first acoustic transmissive body 110
opposite to the sound source side, an end 124 of the second
acoustic transmissive body 120 opposite to the sound source side,
and an end 134 of the third acoustic transmissive body 130 opposite
to the sound source side are all opened. This makes it possible to
achieve a balance in the air between the first space SP10 and the
second space SP20 described later and facilitate the attenuation of
the air as a whole to weaken an abrupt flow of air.
Arrangement
[0116] As illustrated in FIGS. 3, 4, and 5, by forming the first
acoustic transmissive body 110, the second acoustic transmissive
body 120, and the third acoustic transmissive body 130 in such
shapes and sizes as described above, it is possible to arrange
sequentially the first acoustic transmissive body 110, the second
acoustic transmissive body 120, and the third acoustic transmissive
body 130 in an almost concentric (coaxial) manner so that the first
acoustic transmissive body 110 is covered by the second acoustic
transmissive body 120, and the second acoustic transmissive body
120 is covered by the third acoustic transmissive body 130.
[0117] The first acoustic transmissive body 110 and the second
acoustic transmissive body 120 are radially separated from each
other, and the second acoustic transmissive body 120 and the third
acoustic transmissive body 130 are radially separated from each
other.
[0118] As described later, the gun microphone 300 is arranged
inside the first acoustic transmissive body 110 along the
longitudinal direction. The radius of the first acoustic
transmissive body 110 is designed to be slightly larger than the
radius of the gun microphone 300 to be used.
[0119] The first acoustic transmissive body 110 also acts as a hold
member for storing and holding the gun microphone 300 in a
detachable manner. The first acoustic transmissive body 110 has a
cylindrical shape, and the longitudinal length of the first
acoustic transmissive body 110 is larger than the longitudinal
length of the gun microphone 300. Accordingly, the gun microphone
300 can be smoothly attached to or detached from the first acoustic
transmissive body 110, and the entire gun microphone 300 can be
stored in the first acoustic transmissive body 110, while the
leading end of the gun microphone has a gap (air layer).
Acoustic Transmissive Member
[0120] The acoustic transmissive member is formed from a fiber
material obtained by intertwining a raw material containing fibers,
and the air permeability of the fiber material is less than 0.5
s/100 ml. This is because the fiber material used as the acoustic
transmissive material is obtained by interlacing a raw material
with an air permeability of 0.5 s/100 ml and thus provides a fiber
density enough to have an uncountable number of irregular air gaps
to shut off wind of a cause of whistling sounds.
[0121] That is, the acoustic transmissive member made from such a
fiber material acts as a shield or a movement direction converter
(flap) for "wind" of movement of an air molecule mass, and is
almost completely permeable to "sound" of movement of pressure
change (the medium itself does not move but only vibrate).
[0122] When the fiber material has enough freestanding properties
(stiffness), the acoustic transmissive member does not need to be
combined with any other member. However, the acoustic transmissive
member may be configured so that the fiber material is sandwiched
between two net-like bodies, for example.
[0123] The acoustic transmissive member will be described below in
detail.
[0124] As described above, the acoustic transmissive member
transmits a predetermined frequency range (20 to 20 kHz) and the
constituent fiber material has an air permeability of less than 0.5
s/100 ml. With the foregoing properties, the acoustic transmissive
member is significantly improved in acoustic transmissivity. The
air permeability means the time taken for a certain amount of air
to pass through a certain area under a certain pressure. In
particular, it means the time taken for an air of 100 ml to pass
through a sheet-like acoustic transmissive material. The air
permeability is measured by Gurley method stipulated in JIS
P8117.
[0125] The air permeability of less than 0.5 s/100 ml means that it
falls under a measurable range of 0.5 s/100 ml or more of the
measurement device used in the present application.
[0126] The acoustic transmissive member is obtained by interlacing
a raw material containing fibers. For example, a fiber material
with interlaced fibers can be formed by a wet forming method. The
raw material used for manufacture of the fiber material is metallic
fibers or fluorine fibers in this embodiment. The fiber material
used as the acoustic transmissive member has a thickness of 3 mm or
less, preferably 10 .mu.m to 2000 .mu.m, more preferably 20 .mu.m
to 1500 .mu.m. Setting such a thickness makes it possible to obtain
the effect of reducing whistling sounds by a minimum and simple
structural frame with a certain degree of stiffness.
[0127] However, the raw material for the fiber material is not
limited to a metallic fiber or a fluorine fiber, and the thickness
of the fiber material is not limited to the foregoing values.
[0128] Next, the material for metallic fibers as a raw material for
the fiber material will be described.
[0129] To manufacture the acoustic transmissive member from
metallic fibers using a wet forming method, the metallic fiber
material is obtained by processing slurry containing one or two or
more kinds of metallic fibers using a wet forming method. To
manufacture the acoustic transmissive member from metallic fibers
using compression molding, the metallic fiber material is obtained
using heating and pressurizing an aggregate of metallic fibers. In
either case, the resultant metallic fiber material has interlaced
metallic fibers. There is no particular limitation on the shape of
the metallic fiber material but the metallic fiber material is
preferably a metallic fiber sheet.
[0130] The material, structure, and manufacturing method of the
metallic fibers will be described below in detail. The descriptions
in JP 2000-80591 A, Japanese Patent No. 2649768, and Japanese
Patent No. 2562761, which provide the metallic fiber material and
the method for manufacturing the same, are incorporated by
reference in its entirety.
[0131] One or two or more kinds of metallic fibers as the material
for metallic fibers are one or two or more kinds selected from
fibers made from stainless steel, aluminum, brass, copper,
titanium, nickel, gold, platinum, lead, and the like.
[0132] The metallic fiber material has a structure that metallic
fibers are interlaced. The metallic fibers constituting the
metallic fiber has a fiber diameter of 1 .mu.m to 50 .mu.m,
preferably 2 .mu.m to 30 .mu.m, more preferably 8 .mu.m to 20
.mu.m. Such metallic fibers are suited for interlacing, and
interlacing such metallic fibers makes it possible to form a
low-lint metallic fiber sheet with acoustic transmissivity.
[0133] The manufacture of the metallic fiber material by a wet
forming method includes a fiber interlacing process in which the
metallic fibers as a net-like wet sheet are interlaced while slurry
containing one or two or more kinds of metallic fibers is shaped
into a sheet form using a wet forming method.
[0134] In the fiber interlacing process, preferably, high-pressure
jets of water are sprayed onto the metallic fiber sheet after
papermaking, for example. Specifically, a plurality of nozzles is
arranged in a direction orthogonal to the flowing direction of the
sheet to spray high-pressure jets of water at the same time to
interlace the metallic fibers in the entire sheet. That is, when
high-pressure jets of water are sprayed onto the sheet of metallic
fibers crossed one another irregularly in a plane direction by wet
forming, in a Z-axis direction of the sheet, for example, the
metallic fibers onto which the high-pressure jets of water have
been sprayed are oriented in the Z-axis direction. The metallic
fibers oriented in the Z-axis direction gets tangled with the
metallic fibers oriented irregularly in the plane direction. These
fibers are tangled with one another three-dimensionally, that is,
are interlaced to obtain physical strength.
[0135] In addition, the sheet forming method may be selected as
necessary from various methods such as Fourdrinier forming,
cylinder forming, and inclined wire forming. At manufacture of
slurry containing long metallic fibers, dispersiveness of the
metallic fibers in the water may be insufficient. Accordingly, a
small amount of polymer aqueous solution with thickening properties
may be added to the slurry. The polymer includes polyvinyl
pyrrolidone, polyvinyl alcohol, or carboxymethyl cellulose
(CMC).
[0136] According to the method for manufacturing the metallic fiber
material by compression molding, first, the fibers are brought
together and compressed preliminarily to form a web, or the fibers
are impregnated with a binder to bind the fibers and then
compressed preliminarily. After that, the aggregate of metallic
fibers is heated and pressurized to form a metallic fiber sheet.
There is no particular limitation on the binder. For example,
organic binders such as an acrylic adhesive, an epoxy adhesive, and
a urethane adhesive, and inorganic adhesives such as colloidal
silica, water glass, and sodium silicate can be used. Instead of
impregnating the fibers with a binder, the surface of the fibers
may be covered in advance with a thermobonding resin, and an
aggregate of metallic fibers may be layered, and then heated and
bonded. The amount of impregnation with a binder is preferably 5 to
130 g, more preferably 20 to 70 g for a sheet plane weight of 1000
g/m2.
[0137] The aggregate of metallic fibers is heated and pressurized
to form the sheet. The heating conditions are set in consideration
to the binder used, and the drying temperature and curing
temperature of the thermobonding resin. The heating temperature is
generally about 50 to 1000.degree. C. The applied pressure is
adjusted in consideration to the elasticity of the fibers, the
thickness of the acoustic transmissive member, and the light
transmissivity of the acoustic transmissive member. To impregnate
the acoustic transmissive member with a binder by spraying, the
metallic fiber layer is preferably molded to a predetermined
thickness by pressing or the like prior to the spraying.
[0138] In addition, the method for manufacturing the metallic fiber
material preferably includes a sintering process in which, after
the wet forming process described above, the obtained metallic
fiber material is sintered at a temperature equal to or lower than
the melting point of the metallic fibers in vacuum or in a
non-oxidizing atmosphere (in the case of compression molding, a
heating and pressurization process substitutes for the sintering
process). That is, after the wet forming process, the sintering
process is performed to interlace the fibers, which eliminates the
need to add an organic binder or the like to the metallic fiber
material. This makes it possible to manufacture the metallic fiber
material with a metal-specific glossy surface without trouble in
the sintering process that might be caused by a cracked gas from an
organic binder or the like. In addition, the metallic fibers are
interlaced to further improve the strength of the sintered metallic
fiber material. Further, the sintered metallic fiber material is
high in acoustic transmissivity and water-proof property. If not
being sintered, the remaining thickening polymers in the metallic
fiber material might absorb water to deteriorate water-proof
property.
[0139] Next, the material for fluorine fibers as a raw material for
the fiber material will be described.
[0140] In the case of using the fluorine fibers, the fluorine fiber
material becomes a material (paper) in which short fluorine fibers
are oriented in irregular directions and are bonded by thermal
fusion.
[0141] The material and method for manufacturing the fluorine
fibers will be described below in detail. As the material and
method for manufacturing the fluorine fiber material, the
descriptions in JP 63-165598 A are incorporated by reference in its
entirety.
[0142] The fluorine fibers are produced from a thermoplastic
fluorine resin mainly containing polytetrafluoroethylene (PTFE),
tetrafluoroethylene (TFE), perfluoroether (PFE), copolymer of
tetrafluoroethylene and hexafluoropropylene (FEP), copolymer of
tetrafluoroethylene and ethylene or propylene (ETFE),
polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene
(PCTFE), or polyvinyl fluoride (PVF). However, the main ingredients
are not limited to them but may be mixed with the foregoing or
other ones. The fluorine fibers are preferably single fibers with a
fiber length of 1 to 20 mm so that they can be shaped into sheet
form by a wet forming method. In addition, the fluorine fibers
preferably have a fiber diameter of 2 to 30 .mu.m.
[0143] The fluorine fiber material can be produced by mixing and
drying the fluorine fibers and a self-adhesiveness substance by a
wet forming method into a fluorine fiber-mixed sheet material,
subjecting the sheet material to thermal compression bonding at the
softening point of the fluorine fibers or more to fuse thermally
the fluorine fibers, removing the self-adhesiveness substance by
solving in a solvent, and re-drying the material as necessary.
[0144] The self-adhesiveness substance may be natural pulp made
from plant fibers such as wood, cotton, hemp, and straw generally
used for paper making, synthetic pulp or synthetic fibers made from
polyvinyl alcohol (PVA), polyester, aromatic polyamide, acryl or
polyolefin thermoplastic synthetic copolymers, or a paper strength
additive made from natural copolymers or synthetic copolymers.
However, the self-adhesiveness substance is not limited to them as
far as it has self-adhesiveness and can be dispersed in water
together with fluorine fibers.
[0145] The acoustic transmissive member of the present invention is
not limited to the foregoing ones as far as the acoustic
transmissive member includes a fiber material obtained by shaping a
raw material containing fibers into sheet form by a wet forming
method and the fiber material has an air permeability of less than
0.5 s/100 ml.
[0146] As described above, the acoustic transmissive member has a
fiber density enough to have uncountable irregular air gaps and can
shut off wind as a cause of whistling sounds. The acoustic
transmissive member formed from a fiber material acts as a shield
or a movement direction converter (flap) for "wind" as movement of
an air molecule mass, and is almost completely permeable to "sound"
as movement of pressure change (the medium itself does not move but
only vibrate).
[0147] The first acoustic transmissive body 110, the second
acoustic transmissive body 120, and the third acoustic transmissive
body 130 are made of the foregoing acoustic transmissive member and
can basically shut off wind of a cause of whistling sounds.
However, the gun microphone 300 is used outdoor in many cases and
is susceptible to wind. In addition, the gun microphone 300 has an
elongated shape to increase inevitably a large area to contact
wind. Accordingly, it is necessary to provide the first acoustic
transmissive body 110, the second acoustic transmissive body 120,
and the third acoustic transmissive body 130 to form the first
space SP10 and the second space SP20 described later and shut off a
flow of air.
The First Space SP10 and the Second Space SP20
[0148] As describe above, the first acoustic transmissive body 110
and the second acoustic transmissive body 120 are almost concentric
to each other and separated from each other. This makes it possible
to define the first space SP10 in a region sandwiched between the
first acoustic transmissive body 110 and the second acoustic
transmissive body 120 (see FIGS. 4 and 5). The first space SP10 is
almost cylindrical clearance as a whole. The longitudinal length of
the first space SP10 is determined by the longitudinal lengths of
the first acoustic transmissive body 110 and the second acoustic
transmissive body 120. The thickness of side surface of the first
space SP10 constitutes a distance DT10 between the first acoustic
transmissive body 110 and the second acoustic transmissive body
120, which is determined by the difference between the radius of
the first acoustic transmissive body 110 and the radius of the
second acoustic transmissive body 120.
[0149] Similarly, the second space SP20 can be defined in a region
sandwiched between the second acoustic transmissive body 120 and
the third acoustic transmissive body 130 (see FIGS. 4 and 5). The
second space SP20 is an almost cylindrical clearance as a whole.
The longitudinal length of the second space SP20 is determined by
the longitudinal lengths of the second acoustic transmissive body
120 and the third acoustic transmissive body 130. The thickness of
side surface of the second space SP20 constitutes a distance DT20
between the second acoustic transmissive body 120 and the third
acoustic transmissive body 130, which is determined by the
difference between the radius of the second acoustic transmissive
body 120 and the radius of the third acoustic transmissive body
130.
Elastic Foaming Body 140
[0150] The elastic foaming body 140 is generally produced by
foam-molding of a synthetic resin such as polyurethane, and is
formed from a sponge-like elastic foaming body with open cells. The
elastic foaming body 140 is provided over the entire second space
SP20. Therefore, the elastic foaming body 140 has the same shape
and size as those of the second space SP20, and the second space
SP20 is occupied by (charged with) the elastic foaming body
140.
[0151] The elastic foaming body 140 may be charged with the
entirety or part of the second space SP20. For example, the
cylindrical elastic foaming body 140 may be stuck to the inside of
the third acoustic transmissive body 130 to form a gap from the
outside of the second acoustic transmissive body 120.
Alternatively, the elastic foaming body 140 may be provided only on
the central portion or both end portions of the second space SP20.
The elastic foaming body 140 can be provided as appropriate to
attenuate the flow of air in the second space SP20.
Basket 150
[0152] As illustrated in FIGS. 2 and 3, the basket 150 is a
covering body that protects entirely the gun microphone 300, the
first acoustic transmissive body 110, the second acoustic
transmissive body 120, the third acoustic transmissive body 130,
and the elastic foaming body 140. The basket 150 has a function of
transmitting sounds and protecting the gun microphone 300 and
others stored therein.
Shapes and Sizes
[0153] The basket 150 has a leading end portion 152 and a
cylindrical portion 154. The leading end portion 152 has an almost
hemispheric shape. The cylindrical portion 154 has an elongated
cylindrical shape. The leading end portion 152 and the cylindrical
portion 154 are mesh-like with fine gaps to transmit external
sounds.
[0154] The radius of the cylindrical portion 154 is slightly longer
than the radius of the third acoustic transmissive body 130. The
longitudinal length of the cylindrical portion 154 is slightly
larger than the longitudinal lengths of the first acoustic
transmissive body 110, the second acoustic transmissive body 120,
the third acoustic transmissive body 130, and the elastic foaming
body 140.
[0155] The cylindrical portion 154 has a first end 156a and a
second end 156b along the longitudinal direction. The leading end
portion 152 can be detachably attached to the first end 156a of the
cylindrical portion 154. The second end 156b has an almost circular
opening. The first acoustic transmissive body 110, the second
acoustic transmissive body 120, the third acoustic transmissive
body 130, and the elastic foaming body 140 can be inserted and
stored in the cylindrical portion 154 of the basket 150 from the
opening in the second end 156b. In other words, the first acoustic
transmissive body 110, the second acoustic transmissive body 120,
the third acoustic transmissive body 130, and the elastic foaming
body 140 can be entirely covered with the basket 150.
[0156] The first acoustic transmissive body 110, the second
acoustic transmissive body 120, the third acoustic transmissive
body 130, and the elastic foaming body 140 may be fixed in
predetermined positions by a fixing member (not illustrated) in the
basket 150. In this way, the first acoustic transmissive body 110,
the second acoustic transmissive body 120, the third acoustic
transmissive body 130, the elastic foaming body 140, and the basket
150 are integrated. These components may be integrated in a fixed
or detachable manner.
[0157] The opening 332 in the interference tube 320 of the gun
microphone 300 is positioned on the inside of the leading end
portion 152. An acoustic transmissive body (not illustrated) is
also provided on the inside of the leading end portion 152. Besides
the acoustic transmissive body, the elastic foaming body 140 may be
provided on the inside of the leading end portion 152.
[0158] The third acoustic transmissive body 130 may be provide over
the entire inner peripheral surface of the basket 150 so that the
third acoustic transmissive body 130 and the basket 150 can be
integrated. This makes it possible to facilitate the attachment of
the third acoustic transmissive body 130 and keep constantly the
shape of the third acoustic transmissive body 130.
Material
[0159] The basket 150 can transmit sounds and protect the first
acoustic transmissive body 110 and others stored therein. For
example, the basket 150 can be formed from a resin such as
reinforced plastic or a metal such as plastic aluminum.
[0160] The radius of the cylindrical portion 154 is longer than the
radius of the third acoustic transmissive body 130. The
longitudinal length of the cylindrical portion 154 is slightly
larger than the longitudinal lengths of the first acoustic
transmissive body 110, the second acoustic transmissive body 120,
the third acoustic transmissive body 130, and the elastic foaming
body 140.
[0161] Integrating the first acoustic transmissive body 110, the
second acoustic transmissive body 120, the third acoustic
transmissive body 130, the elastic foaming body 140, and the basket
150 makes it possible to form the gun microphone wind shield
100.
[0162] Storing the gun microphone 300 in the first acoustic
transmissive body 110 along the inside of the first acoustic
transmissive body 110 makes it possible to cover the gun microphone
300 with the gun microphone wind shield 100. As illustrated in FIG.
3, the gun microphone 300 is connected to a cable 360 for
outputting electrical signals. The gun microphone wind shield 100
has a size enough to cover the entire gun microphone 300 including
a connection end portion where the cable 360 is connected to the
gun microphone 300.
Flows of Air in the First Space SP10 and the Second Space SP20
(Change in Pressure)
[0163] Referring to FIG. 6, flows of air having entered the first
space SP10 and flows of air having entered the second space SP20
will be describe below.
Flows of Air in the Second Space SP20 (Change in Pressure)
[0164] FIG. 6A is a cross-sectional view of flows of air guided in
the second space SP20 along the longitudinal direction. FIG. 6B is
a cross-sectional view of flows of air guided in the second space
SP20 along the circumferential direction (the direction that
circles around the second acoustic transmissive body 120). For the
sake of clarity, FIGS. 6A and 6B do not illustrate the basket
150.
[0165] The second space SP20 is a region sandwiched between the
second acoustic transmissive body 120 and the third acoustic
transmissive body 130. The second space SP20 is charged with the
elastic foaming body 140.
[0166] The air having passed through the basket 150 first contacts
the acoustic transmissive member in the third acoustic transmissive
body 130. Part of the air in contact is shut off by the acoustic
transmissive member. For example, the shut air moves along the
acoustic transmissive member or is reflected by the acoustic
transmissive member. The remainder of the air not shut off by the
acoustic transmissive member passes through the acoustic
transmissive member. Shutting off part of the air by the acoustic
transmissive member makes it possible to reduce the amount of air
passing through the acoustic transmissive member and entering the
second space SP20 (the elastic foaming body 140).
[0167] The air having entered the second space SP20 then enters the
elastic foaming body 140. The elastic foaming body 140 has open
cells and the air having entered the elastic foaming body 140 moves
along the open cells. The elastic foaming body 140 can control the
flowing direction of the air. In addition, the flow of the air can
be interfered and slowed down gradually by collision with the open
cells. In this way, the elastic foaming body 140 can suppress the
velocity of the air.
[0168] In addition, the second space SP20 (the elastic foaming body
140) is sandwiched between the second acoustic transmissive body
120 and the third acoustic transmissive body 130, and the air
having entered the elastic foaming body 140 travels while being
interfered with by each contact with the second acoustic
transmissive body 120 and the third acoustic transmissive body 130.
In this way, the air having entered the elastic foaming body 140
moves in the second space SP20 while being guided by the second
acoustic transmissive body 120 and the third acoustic transmissive
body 130, and then gradually slows down by the contact with the
second acoustic transmissive body 120, the third acoustic
transmissive body 130, and the elastic foaming body 140 (see FIG.
10).
[0169] The air moving in the second space SP20 has a component LP20
moving along the longitudinal direction of the second acoustic
transmissive body 120 and the third acoustic transmissive body 130
(see FIGS. 6A and 10) and a component AP20 moving along the
circumferential direction of the second acoustic transmissive body
120 and the third acoustic transmissive body 130 (see FIGS. 6B and
10).
Longitudinal Flows of Air in the Second Space SP20
[0170] The second acoustic transmissive body 120 and the third
acoustic transmissive body 130 have an elongated shape adapted to
the gun microphone 300 to cover the gun microphone 300 in the
longitudinal direction. Accordingly, the second space SP20
sandwiched between the second acoustic transmissive body 120 and
the third acoustic transmissive body 130 also has an elongated and
almost cylindrical shape, and the second space SP20 is a space that
exists (extends) in the longitudinal direction according to the
longitudinal length of the gun microphone 300.
[0171] The longitudinal length of the second space SP20 can be
decided depending on the outer shape of the used gun microphone
300. For example, the longitudinal length of the second space SP20
may be almost identical to or slightly larger than the longitudinal
length of the gun microphone 300, and can be ten times or more the
diameter of the gun microphone 300.
[0172] The second space SP20 is a region that allows the air to
flow in the longitudinal direction, and the air having entered the
second space SP20 can move in the longitudinal direction.
Specifically, the air having entered the second space SP20 can be
guided in the longitudinal direction by the second acoustic
transmissive body 120 and the third acoustic transmissive body 130
and gradually slowed down by the elastic foaming body 140.
Providing the second space SP20 as the space where the air can move
sufficiently in the longitudinal direction increases the
opportunities to move and slow down the air gradually, thereby
making the air less likely to enter the first space SP10 from the
second space SP20.
[0173] In this way, the second space SP20 provides a region where
the air can flow in the longitudinal direction, and acts as an air
flow buffer area to make the air less likely to enter the first
space SP10.
Circumferential Flows of Air in the Second Space SP20
[0174] The second acoustic transmissive body 120 and the third
acoustic transmissive body 130 have an almost cylindrical shape and
cover the gun microphone 300 to circle around the gun microphone
300. Accordingly, the second space SP20 sandwiched between the
second acoustic transmissive body 120 and the third acoustic
transmissive body 130 also has an almost cylindrical shape circling
around the gun microphone 300. The second space SP20 is a space
that covers the gun microphone 300 in the circumferential
direction.
[0175] The diametrical thickness of the second space SP20 can be
decided depending on the diameter of the gun microphone 300. For
example, the diametrical thickness of the second space SP20 can be
equal to or less than the diameter of the gun microphone 300 or can
be equal to or less than the radius of the gun microphone 300. In
addition, the diametrical thickness of the second space SP20 may be
larger than the diameter of the gun microphone 300.
[0176] In any case, the second space SP20 only needs to act as an
air flow buffer area and provide a space where the air can move
sufficiently. The space where the air can move sufficiently can be
decided by a balance between the longitudinal length of the second
space SP20 and the diametrical thickness of the second space SP20.
For example, even when the diametrical thickness of the second
space SP20 is shortened, increasing the longitudinal length of the
second space SP20 can provide a space where the air can move
sufficiently.
[0177] The second space SP20 is a region for flowing the air in the
circumferential direction, and the air having entered the second
space SP20 can move along the circumferential direction.
Specifically, the air having entered the second space SP20 can be
guided in the circumferential direction by the second acoustic
transmissive body 120 and the third acoustic transmissive body 130
and gradually slowed down by the elastic foaming body 140.
Providing the second space SP20 as the space where the air can move
sufficiently in the circumferential direction increases the
opportunities to move and slow down the air gradually, thereby
making the air less likely to enter the first space SP10 from the
second space SP20.
[0178] In this way, the second space SP20 provides a region where
the air can flow in the longitudinal direction and the
circumferential direction, and acts as an air flow buffer area to
make the air less likely to enter the first space SP10.
Flows of Air in the Second Space SP20
[0179] As described above, the air having entered the second space
SP20 has the component LP20 that moves along the longitudinal
direction (see FIGS. 6A and 10), and the component AP20 that moves
along the circumferential direction (see FIGS. 6B and 10). The
longitudinal component LP20 and the circumferential component AP20
are determined by the angle and velocity distribution with respect
to the third acoustic transmissive body 130 at the time of entry to
the second space SP20.
[0180] The air of the longitudinal component LP20 moves along the
longitudinal direction while being interfered with by the second
acoustic transmissive body 120 and the third acoustic transmissive
body 130, and is gradually slowed down by the elastic foaming body
140. The air of the circumferential component AP20 moves along the
circumferential direction while being interfered with by the second
acoustic transmissive body 120 and the third acoustic transmissive
body 130, and is gradually slowed down by the elastic foaming body
140. In this way, the second space SP20 acts as a buffer area for
gradually slowing down the air having entered the second space
SP20.
[0181] The air having entered the second space SP20 is not only
slowed down in the second space SP20 but also may flow in the
circumferential direction and then come out from the opposite side
of the second space SP20 to the outside of the basket 150 depending
on the flow velocity, angle, flow amount, and the like (see arrows
OP20 in FIG. 6). The air flowing in the second space SP20 is
interfered with by the second acoustic transmissive body 120 and
becomes less likely to enter the first space SP10.
Flows of Air in the First Space SP10 (Change in Pressure
[0182] FIG. 6A is a cross-sectional view of flows of air guided in
the first space SP10 along the longitudinal direction. FIG. 6B is a
cross-sectional view of flows of air guided in the first space SP10
along the circumferential direction (the direction that circles
around the first acoustic transmissive body 110). For the sake of
clarity, FIGS. 6A and 6B do not illustrate the basket 150.
[0183] The first space SP10 is a region sandwiched between the
first acoustic transmissive body 110 and the second acoustic
transmissive body 120. The first space SP10 is not charged with the
elastic foaming body 140, unlike the second space SP20. Depending
on the use environment of the gun microphone 300, the first space
SP10 may be charged with the elastic foaming body 140 as
appropriate.
[0184] As described above, the second space SP20 (the elastic
foaming body 140) acts as a buffer area for gradually slowing down
the air having entered the second space SP20. Therefore, the air is
less likely to pass through the second acoustic transmissive body
120. However, depending on the use environment of the gun
microphone 300, the air might pass through the second acoustic
transmissive body 120. When having passed through the second
acoustic transmissive body 120, the air also enters the first space
SP10.
[0185] The first space SP10 is sandwiched between the first
acoustic transmissive body 110 and the second acoustic transmissive
body 120, and the air having entered the first space SP10 travels
while being interfered with by each contact with the first acoustic
transmissive body 110 and the second acoustic transmissive body
120. In this way, the air having entered the first space SP10 moves
in the first space SP10 while being attenuated by each contact with
the first acoustic transmissive body 110 and the second acoustic
transmissive body 120 (see FIG. 10).
[0186] As in the second space SP20, the air moving in the first
space SP10 has a component LP10 moving along the longitudinal
direction of the first acoustic transmissive body 110 and the
second acoustic transmissive body 120 (see FIGS. 6A and 10) and a
component AP10 moving along the circumferential direction of the
first acoustic transmissive body 110 and the second acoustic
transmissive body 120 (see FIGS. 6B and 10).
Longitudinal Flows of Air in the First Space SP10
[0187] The first acoustic transmissive body 110 and the second
acoustic transmissive body 120 have an elongated shape adapted to
the gun microphone 300 to cover the gun microphone 300 in the
longitudinal direction. Accordingly, the first space SP10
sandwiched between the first acoustic transmissive body 110 and the
second acoustic transmissive body 120 also has an elongated and
almost cylindrical shape, and the first space SP10 is a space that
exists (extends) in the longitudinal direction according to the
longitudinal length of the gun microphone 300.
[0188] The longitudinal length of the first space SP10 is almost
identical to the longitudinal length of the second space SP20.
Therefore, for example, the longitudinal (axial) length of the
first space SP10 may be almost identical to or slightly larger than
the longitudinal length of the gun microphone 300, and can be ten
times or more the diameter of the gun microphone 300.
[0189] The first space SP10 is a region that allows the air to flow
in the longitudinal direction, and the air having entered the first
space SP10 can move in the longitudinal direction. Specifically,
the air having entered the first space SP10 can be guided in the
longitudinal direction by the first acoustic transmissive body 110
and the second acoustic transmissive body 120 and gradually slowed
down by contact with the first acoustic transmissive body 110 and
the second acoustic transmissive body 120. Providing the first
space SP10 as the space where the air can move sufficiently in the
longitudinal direction increases the opportunities to move and slow
down the air gradually, which makes the air less likely to leak
from the first space SP10 toward the gun microphone 300.
[0190] In this way, the first space SP10 provides a region where
the air can flow in the longitudinal direction, and acts as an air
flow buffer area to make the air less likely to enter the gun
microphone 300.
Circumferential Flows of Air in the First Space SP10
[0191] The first acoustic transmissive body 110 and the second
acoustic transmissive body 120 have an almost cylindrical shape and
cover the gun microphone 300 to circle around the gun microphone
300. Accordingly, the first space SP10 sandwiched between the first
acoustic transmissive body 110 and the second acoustic transmissive
body 120 also has an almost cylindrical shape circling around the
gun microphone 300. The first space SP10 is a space that covers the
gun microphone 300 in the circumferential direction.
[0192] The diametrical thickness of the first space SP10 can be
decided depending on the diameter of the gun microphone 300. For
example, the diametrical thickness of the first space SP10 can be
equal to or less than the diameter of the gun microphone 300 or can
be equal to or less than the radius of the gun microphone 300. In
addition, the diametrical thickness of the first space SP10 may be
larger than the diameter of the gun microphone 300.
[0193] The first space SP10 only needs to act as an air flow buffer
area and provide a space where the air can move sufficiently. The
space where the air can move sufficiently can be decided by a
balance between the longitudinal length of the first space SP10 and
the diametrical thickness of the first space SP10. For example,
even when the diametrical thickness of the first space SP10 is
shortened, increasing the longitudinal length of the first space
SP10 can provide a space where the air can move sufficiently.
[0194] Further, the size of the first space SP10 may be decided
depending on the size of the second space SP20. For example, when
the size of the second space SP20 is significantly larger than the
size of the first space SP10, the second space SP20 can keep most
of the air having entered the second space SP20 to prevent the air
from entering the first space SP10. In addition, when the size of
the second space SP20 is smaller than the size of the first space
SP10, the second space SP20 can keep part of the air having entered
the second space SP20 to prevent the air from entering the first
space SP10. The size of the first space SP10 and the size of the
second space SP20 can be decided according to the use environment
of the gun microphone 300 and the structure of the interference
tube 320.
[0195] The first space SP10 is a region for flowing the air in the
circumferential direction, and the air having entered the first
space SP10 can move along the circumferential direction.
Specifically, the air having entered the first space SP10 can be
guided in the circumferential direction by the first acoustic
transmissive body 110 and the second acoustic transmissive body 120
and gradually slowed down by contact with the first acoustic
transmissive body 110 and the second acoustic transmissive body
120. Providing the first space SP10 as the space where the air can
move sufficiently in the circumferential direction increases the
opportunities to move and slow down the air gradually, which makes
the air less likely to leak from the first space SP10 toward the
gun microphone 300.
[0196] In this way, the first space SP10 provides a region where
the air can flow in the circumferential direction, and acts as an
air flow buffer area to make the air less likely to enter the gun
microphone 300.
Flows of Air in the First Space SP10
[0197] As described above, the air having entered the first space
SP10 has the component LP10 that moves along the longitudinal
direction (see FIGS. 6A and 10), and the component AP10 that moves
along the circumferential direction (see FIGS. 6B and 10). The
longitudinal component LP10 and the circumferential component AP10
are determined by the angle and velocity distribution with respect
to the second acoustic transmissive body 120 at the time of entry
to the first space SP10.
[0198] The air of the longitudinal component LP10 moves along the
longitudinal direction while being interfered with by the first
acoustic transmissive body 110 and the second acoustic transmissive
body 120, and is gradually slowed down by the elastic foaming body
140. The air of the circumferential component AP10 moves along the
circumferential direction while being interfered with by the first
acoustic transmissive body 110 and the second acoustic transmissive
body 120, and is gradually slowed down by the elastic foaming body
140. In this way, the first space SP10 acts as a buffer area for
gradually slowing down the air having entered the first space
SP10.
[0199] The air having entered the first space SP10 is not only
slowed down in the first space SP10 but also may flow in the
circumferential direction and then come out from the opposite side
of the first space SP10 to the second space SP20 depending on the
flow velocity, angle, flow amount, and the like (see arrows OP10 in
FIG. 6). The air flowing in the first space SP10 is interfered with
by the first acoustic transmissive body 110 and becomes less likely
to reach the gun microphone 300.
[0200] Wind noise is generated by the air (wind) in direct contact
with the diaphragm of the microphone body 310. As described above,
first of all, the second space SP20 (the elastic foaming body 140)
suppresses the movement of the air having entered the second space
SP20 and then the first space SP10 suppresses the movement of the
air having entered the first space SP10. In this way, the first
space SP10 and the second space SP20 suppress the movement of the
air and make the air less likely to leak toward the gun microphone
300. This makes the movement of the air less likely to transfer to
the diaphragm of the microphone body 310 of the gun microphone 300
and prevents wind noise.
Suppression of Negative Pressure Fluctuation in the First Space
SP10 and the Second Space SP20
[0201] As described above, air flows into the microphone body 310
of the gun microphone 300 to vibrate the diaphragm and generate
wind noise. Further, wind noise is generated not only by the direct
inflow of air but also by fluctuation in the surrounding
pressure.
[0202] Slight pressure fluctuation, specifically, negative pressure
fluctuation that occurs around the gun microphone 300 may vibrate
the diaphragm of the microphone body 310 to generate wind noise.
The gun microphone wind shield 100 suppresses such negative
pressure fluctuation and prevents the occurrence of wind noise by
the negative pressure fluctuation.
[0203] First, when air flows outside the basket 150 to generate
negative pressure fluctuation in the second space SP20, the
longitudinal movement of the air and the circumferential movement
of the air are generated in the second space SP20 (the elastic
foaming body 140) to suppress the negative pressure fluctuation in
the second space SP20. Suppressing the negative pressure
fluctuation in the second space SP20 makes it possible to prevent
the occurrence of negative pressure fluctuation in the first
space.
[0204] In addition, even when the negative pressure fluctuation in
the second space SP20 is transferred to the first space SP10 to
cause negative pressure fluctuation in the first space SP10, the
longitudinal movement of the air and the circumferential movement
of the air are generated in the first space SP10 to suppress the
negative pressure fluctuation in the first space SP10. Suppressing
the negative pressure fluctuation in the first space SP10 makes it
possible to prevent the transfer of the negative pressure
fluctuation to the diaphragm of the gun microphone 300.
[0205] Causing proactively the longitudinal movement of the air and
the circumferential movement of the air in each of the first space
SP10 and the second space SP20 makes it possible to suppress
negative pressure fluctuation. The second space SP20 (the elastic
foaming body 140) has an elongated shape that can move the air
sufficiently in the longitudinal direction. The second acoustic
transmissive body 120, the third acoustic transmissive body 130,
and the elastic foaming body 140 contact the moving air to slow
down the air gradually.
[0206] The first space SP10 also has an elongated shape that can
move the air sufficiently in the longitudinal direction. The first
acoustic transmissive body 110 and the second acoustic transmissive
body 120 contact the moving air to slow down the air gradually.
[0207] The gun microphone wind shield 100 has the first space SP10
and the second space SP20 to move the air sufficiently in the
longitudinal direction and slow down the moving air, thereby
absorbing negative pressure fluctuation. In this way, providing the
first space SP10 and the second space SP20 that act as two-step
buffer areas, negative pressure fluctuation is suppressed in a
stepwise manner.
[0208] Accordingly, the gun microphone wind shield 100 has the
first space SP10 and the second space SP20 as described above to
make air less likely to leak to the gun microphone 300 and prevent
wind noise generated from the diaphragm vibrated by the air.
[0209] Further, even in the case where the air does not enter the
gun microphone 300, the air may flow around the gun microphone 300
to generate negative pressure fluctuation that vibrates the
diaphragm. In such a case, the formation of the first space SP10
and the second space SP20 makes it possible to suppress negative
pressure fluctuation and prevent the occurrence of wind noise due
to the negative pressure fluctuation.
[0210] In this way, the first space SP10 and the second space SP20
can not only shut off the movement of the air but also suppress the
occurrence of negative pressure fluctuation.
Grip Vibration-Proof Structure 400
[0211] FIG. 11 is a side view of the basket 150 and the grip
vibration-proof structure 400. FIG. 12 is a perspective view of the
basket 150 and the grip vibration-proof structure 400. FIG. 13 is
an enlarged side view of structure of the grip portion 410. FIG. 14
is a perspective view of the entire grip vibration-proof structure
400. FIG. 15 is a front view of the first acoustic transmissive
body 110 and the second acoustic transmissive body 120 attached to
the elastic hold body 434. FIG. 16 is a perspective view of the
first acoustic transmissive body 110 attached to the elastic hold
body 434. FIG. 17 is a perspective view of the end of the basket
150.
[0212] The grip vibration-proof structure 400 can be detachably
attached to the basket 150 of the gun microphone wind shield 100.
The grip vibration-proof structure 400 includes a grip portion 410
and a hold portion 430.
[0213] The user can hold and support the grip portion 410 with
his/her hand to direct the gun microphone 300 with the gun
microphone wind shield 100 to a desired sound source. The user can
hold indirectly the gun microphone 300 via the gun microphone wind
shield 100 due to the grip portion 410 and prevent shock and
solid-borne sounds generated during use from being directly
transferred to the gun microphone 300.
[0214] The hold portion 430 of the grip vibration-proof structure
400 attenuates shock and solid-borne sounds applied to the gun
microphone wind shield 100. This prevents the shock and solid-borne
sounds from being picked up as noise by the gun microphone 300. The
grip vibration-proof structure 400 includes a grip portion 410 and
a hold portion 430.
Slit 158
[0215] As illustrated in FIG. 12, the basket 150 has a slit 158
along the longitudinal direction of the basket 150. The slit 158 is
formed to extend from the second end 156b of the basket 150 to a
retainment position 160 in the middle of the basket 150. Attaching
the grip portion 410 and the hold portion 430 to sandwich the
basket 150 via the slit 158 allows the grip vibration-proof
structure 400 to be detachably attached to the basket 150.
Grip Portion 410
[0216] The grip portion 410 mainly has a grip 412, a coupling body
414, and a vibration absorber 416. The grip 412 and the coupling
body 414 are arranged outside the basket 150 while the grip
vibration-proof structure 400 is attached to the basket 150.
[0217] The grip 412 is a member that can be handheld by the user of
the gun microphone 300 and the gun microphone wind shield 100. The
user can handhold the grip 412 to direct the gun microphone 300 and
the gun microphone wind shield 100 to a desired direction.
[0218] The grip 412 is rotatably provided on the coupling body 414.
For example, the grip 412 is rotatably attached to the coupling
body 414 via a retainment member such as a bolt and a nut.
Attaching rotatably the grip 412 to the coupling body 414 allows
the user to set the desired angle formed between the grip 412 and
the gun microphone 300 having the gun microphone wind shield 100
and to direct the gun microphone 300 to a sound source at a high
position or a low position.
[0219] The coupling body 414 has an elongated shape and can be
attached to the outer surface of the basket 150 along the
longitudinal direction. As described later, the coupling body 414
can be attached to a coupling support body 432 of the hold portion
430.
[0220] The vibration absorber 416 is made from an elastically
deformable resin such as rubber. The vibration absorber 416 has an
elongated and plate-like shape. The vibration absorber 416 is
sandwiched between the coupling body 414 and the outer surface of
the basket 150, in contact with the basket 150. The vibration
absorber 416 absorbs a certain degree of shock and solid-borne
sounds to make the shock and solid-borne sounds less likely to
transfer to the hold portion 430.
Hold Portion 430
[0221] The hold portion 430 mainly has the coupling support body
432, the elastic hold bodies 434, and the brackets 440. The
coupling support body 432, the elastic hold bodies 434, and the
brackets 440 are arranged inside the basket 150 while the grip
vibration-proof structure 400 is attached to the basket 150.
[0222] The coupling support body 432 has an elongated shape and can
be attached to the inner surface of the basket 150 along the
longitudinal direction. The coupling body 414 of the grip portion
410 is arranged on the outer surface of the basket 150 along the
longitudinal direction, and the coupling support body 432 is
arranged on the inner surface of the basket 150 along the
longitudinal direction. The coupling body 414 and the coupling
support body 432 are opposed to each other via the slit 158. The
coupling body 414 has a plurality of openings (not illustrated),
and the coupling support body 432 has a plurality of screw holes
(not illustrated) corresponding to the openings in the coupling
body 414. Fastening screws (not illustrated) into the screw holes
in the coupling support body 432 via the openings in the coupling
body 414 allows the hold portion 430 to be detachably attached to
the grip portion 410 and allows the grip vibration-proof structure
400 to be detachably provided on the basket 150.
[0223] The elastic hold bodies 434 are attached to the coupling
support body 432. Each of the elastic hold bodies 434 has an inner
arc body 436 and an outer arc body 438. The radius of the inner arc
body 436 is smaller than the radius of the outer arc body 438, and
the elastic hold bodies 434 have a shape in which the inner arc
body 436 and the outer arc body 438 are coupled together. The outer
arc body 438 is attached to the coupling support body 432. The
inner arc body 436 is attached to the brackets 440 described
later.
[0224] The inner arc body 436 and the outer arc body 438 are both
made of an elastically deformable resin. The inner arc body 436 and
the outer arc body 438 elastically deform to absorb external shock
and solid-borne sounds, make the shock and solid-borne sounds less
likely to transfer to the gun microphone 300, and prevent the shock
and solid-borne sounds from being picked up as noise. The function
of the elastic hold bodies 434 will be described later.
[0225] The brackets 440 are attached to the inner arc body 436.
Each of the brackets 440 has an elongate and almost cylindrical
shape with a slit on the side surface.
[0226] The first acoustic transmissive body 110 is attached to the
insides of the brackets 440, and the second acoustic transmissive
body 120 is attached to the outsides of the brackets 440. Attaching
the first acoustic transmissive body 110 and the second acoustic
transmissive body 120 to the brackets 440 makes it possible to keep
the first acoustic transmissive body 110 and the second acoustic
transmissive body 120 in a constant shape.
[0227] In addition, attaching the first acoustic transmissive body
110 and the second acoustic transmissive body 120 with the brackets
440 therebetween makes it possible to form the first space SP1
stably between the first acoustic transmissive body 110 and the
second acoustic transmissive body 120 and keep the volume of the
first space SP1 constant.
[0228] As described above, the first acoustic transmissive body 110
has an elongated and almost cylindrical shape. A ring 450 is
provided at a plurality of places on the outside of the first
acoustic transmissive body 110 along the longitudinal direction.
The rings 450 can prevent the first acoustic transmissive body 110
from being deformed and narrowed. In addition, applying an adhesive
to the insides of the rings 450 makes it possible to prevent the
first acoustic transmissive body 110 from being displaced in the
longitudinal direction. Providing the plurality of rings 450 makes
it possible to keep the shape of the first acoustic transmissive
body 110 constant and hold the gun microphone 300 stably and allow
the gun microphone 300 to be easily detached. Other rings (not
illustrated) may be provided inside the first acoustic transmissive
body 110 to support the first acoustic transmissive body 110 so
that it is possible to prevent the first acoustic transmissive body
110 from being deformed and narrowed without having to apply an
adhesive to the insides of the rings 450.
[0229] Each of the rings 450 has an opening (not illustrated) via
which sounds can be transmitted. As described above, the gun
microphone 300 is arranged inside the first acoustic transmissive
body 110. Using the rings 450 with openings makes it possible to
maintain the sound transmissivity of the first acoustic
transmissive body 110.
Shock Applied to the Gun Microphone Wind Shield 100
[0230] As described above, each of the elastic hold bodies 434 has
the inner arc body 436 and the outer arc body 438. The inner arc
body 436 and the outer arc body 438 elastically deform according to
applied force. When the grip 412 is grasped by the operator to
change the orientation of the gun microphone 300 or switch the gun
microphone 300 from one hand to the other, some shock may be
applied to the grip 412. In addition, solid-borne sounds generated
by wind and propagated as vibration through a solid body are picked
up as wind noise.
[0231] The gun microphone wind shield 100 has the vibration
absorber 416 and the elastic hold bodies 434 so that shock and
solid-borne sounds are attenuated by the vibration absorber 416 and
the elastic hold bodies 434 so as not to transfer to the gun
microphone 300. The functions of the vibration absorber 416 and the
elastic hold bodies 434 will be described below.
Function of the Vibration Absorber 416
[0232] The vibration absorber 416 is formed from a resin such as
rubber and is elastically deformable. The vibration absorber 416 is
sandwiched between the coupling body 414 and the outer surface of
the basket 150, in contact with the basket 150. The shock and
solid-borne sounds applied to the grip 412 are attenuated and
gradually absorbed by the vibration absorber 416 repeating elastic
deformation. Absorbing the shock and solid-borne sounds by the
vibration absorber 416 makes the shock and solid-borne sounds less
likely to transfer to the hold portion 430.
Function of the Elastic Hold Bodies 434
[0233] Each of the elastic hold bodies 434 has the inner arc body
436 and the outer arc body 438. The inner arc body 436 and the
outer arc body 438 elastically deform according to applied force.
When the grip 412 is grasped by the operator to change the
orientation of the gun microphone 300 or switch the gun microphone
300 from one hand to the other, some shock may be applied to the
grip 412. In addition, solid-borne sounds may be applied to the
grip 412.
[0234] The inner arc bodies 436 and the outer arc bodies 438 are
constituted by a resin and are elastically deformable. The shock
and solid-borne sounds transferred via the coupling support body
432 are first transferred to the outer arc bodies 438. The outer
arc bodies 438 elastically deform due to the shock to attenuate
gradually the shock. Similarly, when shock is transferred from the
outer arc bodies 438 to the inner arc bodies 436, the inner arc
bodies 436 elastically deform due to the shock to attenuate
gradually the shock. Even when shock is transferred to the elastic
hold bodies 434 via the coupling support body 432, the inner arc
bodies 436 and the outer arc bodies 438 prevent the shock from
being transferred to the brackets 440 so that the shock is not
picked up as noise by the gun microphone. In addition, while
solid-borne sounds are transferred as vibration to the outer arc
bodies 438 and the inner arc bodies 436, vibration energy is
gradually absorbed and attenuated by the outer arc bodies 438 and
the inner arc bodies 436.
Second Embodiment
[0235] In the gun microphone wind shield 100 of the first
embodiment, the elastic foaming body 140 is provided in the second
space SP20. In a second embodiment, the elastic foaming body 140
may not be provided in the second space SP20.
Gun Microphone Wind Shield 200
[0236] As illustrated in FIGS. 7, 8, and 9, in a gun microphone
wind shield 200 of the second embodiment, the elastic foaming body
140 is not provided in the first space SP10 or the second space
SP20. The configuration of the gun microphone wind shield 200 in
the second embodiment and the configuration of the gun microphone
wind shield 100 in the first embodiment are different in the
presence or absence of the elastic foaming body 140. That is, a
first acoustic transmissive body 110, a second acoustic
transmissive body 120, a third acoustic transmissive body 130, and
a basket 150 have shapes, materials, and functions similar to those
of the first embodiment, and are arranged in manners similar to
those of the first embodiment, and are given the same reference
signs as those of the first embodiment.
[0237] Like the gun microphone wind shield 100 in the first
embodiment, a first space SP10 is defined in a region sandwiched
between the first acoustic transmissive body 110 and the second
acoustic transmissive body 120. A second space SP20 is defined in a
region sandwiched between the second acoustic transmissive body 120
and the third acoustic transmissive body 130.
[0238] A distance DT10 between the first acoustic transmissive body
110 and the second acoustic transmissive body 120 and a distance
DT20 between the second acoustic transmissive body 120 and the
third acoustic transmissive body 130 can be decided as appropriate
according to the presence or absence of the elastic foaming body
140.
[0239] In the gun microphone wind shield 200 of the second
embodiment as well as the gun microphone wind shield 100 of the
first embodiment, the air having entered the first space SP10 has a
component LP10 that moves along the longitudinal direction (see
FIGS. 6A and 10) and a component AP10 that moves long the
circumferential direction (see FIGS. 6B and 10), and the air having
entered the second space SP20 has a component LP20 that moves along
the longitudinal direction (see FIGS. 6A and 10) and a component
AP20 that moves long the circumferential direction (see FIGS. 6B
and 10).
[0240] Setting appropriately the distance of the first space SP10
and the distance of the second space SP20 makes it possible to
produce the component LP10 moving along the longitudinal direction,
the component AP10 moving along the circumferential direction, the
component LP20 moving along the longitudinal direction, and the
component AP20 moving along the circumferential direction, which
makes the air less likely to enter the gun microphone 300, thereby
shutting off whistling sounds properly.
Modification Examples
[0241] In the first embodiment, the elastic foaming body 140 is
provided only in the second space SP20, and the elastic foaming
body 140 is not provided in the first space SP10. In the second
embodiment, the elastic foaming body 140 is not provided in the
first space SP10 or the second space SP20.
[0242] Besides, the elastic foaming body 140 may be provided only
in the first space SP10 but may not be provided in the second space
SP20, or the elastic foaming body 140 may be provided both in the
first space SP10 and the second space SP20.
[0243] In either case, setting appropriately the distance of the
first space SP10 and the distance of the second space SP20
according to the presence or absence of the elastic foaming body
140 makes it possible to produce the component LP10 moving along
the longitudinal direction, the component AP10 moving along the
circumferential direction, the component LP20 moving along the
longitudinal direction, and the component AP20 moving along the
circumferential direction, which makes the air less likely to enter
the gun microphone 300, thereby shutting off whistling sounds
properly.
REFERENCE SIGNS LIST
[0244] 100 Gun microphone wind shield [0245] 110 First acoustic
transmissive body [0246] 120 Second acoustic transmissive body
[0247] 130 Third acoustic transmissive body [0248] 140 Elastic
foaming body [0249] 150 Basket [0250] 300 Gun microphone [0251]
SP10 First space [0252] SP20 Second space
* * * * *